97. Euphorbia commutata Engelmann in A. Gray, Manual ed. 2. 389. 1856.
Tinted woodland spurge Tinted woodland spurge
Galarhoeus austrinus (Small) Small; G. commutatus (Engelmann) Small ex Rydberg; Tithymalus commutatus (Engelmann) Klotzsch & Garcke
Herbs, usually biennial, occasionally annual, with taproot. Stems erect or ascending, decumbent and often branched near base, 10–40 cm, glabrous. Leaves: petiole usually 5–10 mm, 0–1 mm distally; blade usually oblanceolate to obovate, rarely ovate, 5–30 × 3–10 mm, base broadly attenuate, margins entire, apex usually obtuse to rounded, occasionally slightly retuse, surfaces glabrous; venation pinnate, midvein prominent. Cyathial arrangement: terminal pleiochasial branches (2–)3(–4), 1–3+ times 2-branched; pleiochasial bracts similar in shape and size to distal leaves; dichasial bracts distinct to basally subconnate, not imbricate, widely ovate, rhombic, or reniform, base cordate, rarely slightly perfoliate, margins entire, apex obtuse to rounded, mucronulate; axillary cymose branches 0–5. Cyathia: peduncle 0.5–1 mm. Involucre campanulate, 1.7–2.5 × 1.5–2.5 mm, glabrous; glands 4, crescent-shaped; 0.6–1 × 0.8–1.5 mm; horns divergent, 0.5–1.1 mm. Staminate flowers 9–15. Pistillate flowers: ovary glabrous; styles 0.9–1.3 mm, 2-fid. Capsules ovoid-globose, 2.5–3.2 × 3 mm, slightly lobed; cocci rounded to ± flattened, smooth, glabrous; columella 1.5–2 mm. Seeds white to gray, broadly oblong-elliptic to ovoid or nearly globose, 1.5–2 × 1.3–1.6 mm, strongly small-pitted; caruncle irregularly winglike, conic, 0.6–1 × 0.7–0.9 mm.
Flowering and fruiting spring–summer. Bottomland and upland forests, bluffs and ledges, stream banks, glades, rarely fen margins; 50–1000 m; Ont.; Ala., Ark., Fla., Ga., Ill., Ind., Iowa, Ky., La., Md., Mich., Miss., Mo., N.C., Ohio, Okla., Pa., S.C., Tenn., Va., W.Va., Wis.